MATHEMATICAL MODELS APPLIED TO THE DECOMPOSITION STUDIES OF AQUATIC MACROPHYTES.

Abstract

This revision aimed at analyzing the mathematical models usually used in the handling data of degradation experiments with aquatic macrophytes. The mathematical models that describe the decomposition process of aquatic macrophytes frequently observed in literature are: single and double exponential models. Through a meta analysis from results of 37 experiments of aquatic macrophytes decomposition the exponential models were compared. The analysis of the parameters of each model indicated that: i) the use of the single exponential model does not represent adequately the fast losses of mass that occur in the beginning of process, relative to leaching from the detritus and ii) the decomposition coefficients related with of refractory fractions (from double exponential model) was minor than that obtained to the single exponential model generating, consequently, incremented half-time (ca. 2.3 times) of process.